2 * Copyright (c) 1988 University of Utah.
3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
6 * This code is derived from software contributed to Berkeley by
7 * the Systems Programming Group of the University of Utah Computer
8 * Science Department, and code derived from software contributed to
9 * Berkeley by William Jolitz.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * from: Utah $Hdr: mem.c 1.13 89/10/08$
36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91
37 * $FreeBSD: src/sys/i386/i386/mem.c,v 1.79.2.9 2003/01/04 22:58:01 njl Exp $
44 #include <sys/param.h>
45 #include <sys/systm.h>
48 #include <sys/fcntl.h>
49 #include <sys/filio.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.h>
52 #include <sys/memrange.h>
55 #include <sys/random.h>
56 #include <sys/signalvar.h>
58 #include <sys/vnode.h>
59 #include <sys/sysctl.h>
61 #include <sys/signal2.h>
62 #include <sys/mplock2.h>
66 #include <vm/vm_extern.h>
69 static d_open_t mmopen;
70 static d_close_t mmclose;
71 static d_read_t mmread;
72 static d_write_t mmwrite;
73 static d_ioctl_t mmioctl;
75 static d_mmap_t memmmap;
77 static d_kqfilter_t mmkqfilter;
78 static int memuksmap(cdev_t dev, vm_page_t fake);
81 static struct dev_ops mem_ops = {
82 { "mem", 0, D_MPSAFE },
88 .d_kqfilter = mmkqfilter,
97 static cdev_t zerodev = NULL;
99 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
100 static int mem_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
101 static int random_ioctl (cdev_t, u_long, caddr_t, int, struct ucred *);
103 struct mem_range_softc mem_range_softc;
105 static int seedenable;
106 SYSCTL_INT(_kern, OID_AUTO, seedenable, CTLFLAG_RW, &seedenable, 0, "");
109 mmopen(struct dev_open_args *ap)
111 cdev_t dev = ap->a_head.a_dev;
114 switch (minor(dev)) {
118 * /dev/mem and /dev/kmem
120 if (ap->a_oflags & FWRITE) {
121 if (securelevel > 0 || kernel_mem_readonly)
128 * /dev/kpmap can only be opened for reading.
130 if (ap->a_oflags & FWRITE)
135 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0);
138 if (securelevel > 0 || kernel_mem_readonly) {
142 error = cpu_set_iopl();
152 mmclose(struct dev_close_args *ap)
154 cdev_t dev = ap->a_head.a_dev;
157 switch (minor(dev)) {
159 error = cpu_clr_iopl();
170 mmrw(cdev_t dev, struct uio *uio, int flags)
180 while (uio->uio_resid > 0 && error == 0) {
182 if (iov->iov_len == 0) {
185 if (uio->uio_iovcnt < 0)
189 switch (minor(dev)) {
192 * minor device 0 is physical memory, /dev/mem
195 v &= ~(long)PAGE_MASK;
196 pmap_kenter((vm_offset_t)ptvmmap, v);
197 o = (int)uio->uio_offset & PAGE_MASK;
198 c = (u_int)(PAGE_SIZE - ((uintptr_t)iov->iov_base & PAGE_MASK));
199 c = min(c, (u_int)(PAGE_SIZE - o));
200 c = min(c, (u_int)iov->iov_len);
201 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio);
202 pmap_kremove((vm_offset_t)ptvmmap);
207 * minor device 1 is kernel memory, /dev/kmem
209 vm_offset_t saddr, eaddr;
215 * Make sure that all of the pages are currently
216 * resident so that we don't create any zero-fill
219 saddr = trunc_page(uio->uio_offset);
220 eaddr = round_page(uio->uio_offset + c);
225 * Make sure the kernel addresses are mapped.
226 * platform_direct_mapped() can be used to bypass
227 * default mapping via the page table (virtual kernels
228 * contain a lot of out-of-band data).
231 if (uio->uio_rw != UIO_READ)
232 prot |= VM_PROT_WRITE;
233 error = kvm_access_check(saddr, eaddr, prot);
236 error = uiomove((caddr_t)(vm_offset_t)uio->uio_offset,
242 * minor device 2 (/dev/null) is EOF/RATHOLE
244 if (uio->uio_rw == UIO_READ)
250 * minor device 3 (/dev/random) is source of filth
251 * on read, seeder on write
254 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
255 c = min(iov->iov_len, PAGE_SIZE);
256 if (uio->uio_rw == UIO_WRITE) {
257 error = uiomove(buf, (int)c, uio);
261 error = add_buffer_randomness_src(buf, c, RAND_SRC_SEEDING);
262 } else if (error == 0) {
266 poolsize = read_random(buf, c);
270 if ((flags & IO_NDELAY) != 0)
271 return (EWOULDBLOCK);
274 c = min(c, poolsize);
275 error = uiomove(buf, (int)c, uio);
280 * minor device 4 (/dev/urandom) is source of muck
281 * on read, writes are disallowed.
283 c = min(iov->iov_len, PAGE_SIZE);
284 if (uio->uio_rw == UIO_WRITE) {
288 if (CURSIG(curthread->td_lwp) != 0) {
290 * Use tsleep() to get the error code right.
291 * It should return immediately.
293 error = tsleep(&rand_bolt, PCATCH, "urand", 1);
294 if (error != 0 && error != EWOULDBLOCK)
298 buf = kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
299 poolsize = read_random_unlimited(buf, c);
300 c = min(c, poolsize);
301 error = uiomove(buf, (int)c, uio);
303 /* case 5: read/write not supported, mmap only */
304 /* case 6: read/write not supported, mmap only */
307 * minor device 12 (/dev/zero) is source of nulls
308 * on read, write are disallowed.
310 if (uio->uio_rw == UIO_WRITE) {
315 zbuf = (caddr_t)kmalloc(PAGE_SIZE, M_TEMP,
318 c = min(iov->iov_len, PAGE_SIZE);
319 error = uiomove(zbuf, (int)c, uio);
326 iov->iov_base = (char *)iov->iov_base + c;
328 uio->uio_offset += c;
337 mmread(struct dev_read_args *ap)
339 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
343 mmwrite(struct dev_write_args *ap)
345 return(mmrw(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag));
348 /*******************************************************\
349 * allow user processes to MMAP some memory sections *
350 * instead of going through read/write *
351 \*******************************************************/
353 static int user_kernel_mapping(int num, vm_ooffset_t offset,
354 vm_ooffset_t *resultp);
359 memmmap(struct dev_mmap_args *ap)
361 cdev_t dev = ap->a_head.a_dev;
365 switch (minor(dev)) {
368 * minor device 0 is physical memory
370 ap->a_result = atop(ap->a_offset);
375 * minor device 1 is kernel memory
377 ap->a_result = atop(vtophys(ap->a_offset));
383 * minor device 5 is /dev/upmap (see sys/upmap.h)
384 * minor device 6 is /dev/kpmap (see sys/upmap.h)
387 error = user_kernel_mapping(minor(dev), ap->a_offset, &result);
388 ap->a_result = atop(result);
400 memuksmap(cdev_t dev, vm_page_t fake)
405 switch (minor(dev)) {
408 * minor device 0 is physical memory
410 fake->phys_addr = ptoa(fake->pindex);
415 * minor device 1 is kernel memory
417 fake->phys_addr = vtophys(ptoa(fake->pindex));
423 * minor device 5 is /dev/upmap (see sys/upmap.h)
424 * minor device 6 is /dev/kpmap (see sys/upmap.h)
427 error = user_kernel_mapping(minor(dev),
428 ptoa(fake->pindex), &result);
429 fake->phys_addr = result;
439 mmioctl(struct dev_ioctl_args *ap)
441 cdev_t dev = ap->a_head.a_dev;
446 switch (minor(dev)) {
448 error = mem_ioctl(dev, ap->a_cmd, ap->a_data,
449 ap->a_fflag, ap->a_cred);
453 error = random_ioctl(dev, ap->a_cmd, ap->a_data,
454 ap->a_fflag, ap->a_cred);
466 * Operations for changing memory attributes.
468 * This is basically just an ioctl shim for mem_range_attr_get
469 * and mem_range_attr_set.
472 mem_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
475 struct mem_range_op *mo = (struct mem_range_op *)data;
476 struct mem_range_desc *md;
478 /* is this for us? */
479 if ((cmd != MEMRANGE_GET) &&
480 (cmd != MEMRANGE_SET))
483 /* any chance we can handle this? */
484 if (mem_range_softc.mr_op == NULL)
487 /* do we have any descriptors? */
488 if (mem_range_softc.mr_ndesc == 0)
493 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
495 md = (struct mem_range_desc *)
496 kmalloc(nd * sizeof(struct mem_range_desc),
497 M_MEMDESC, M_WAITOK);
498 error = mem_range_attr_get(md, &nd);
500 error = copyout(md, mo->mo_desc,
501 nd * sizeof(struct mem_range_desc));
502 kfree(md, M_MEMDESC);
504 nd = mem_range_softc.mr_ndesc;
510 md = (struct mem_range_desc *)kmalloc(sizeof(struct mem_range_desc),
511 M_MEMDESC, M_WAITOK);
512 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
513 /* clamp description string */
514 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
516 error = mem_range_attr_set(md, &mo->mo_arg[0]);
517 kfree(md, M_MEMDESC);
524 * Implementation-neutral, kernel-callable functions for manipulating
525 * memory range attributes.
528 mem_range_attr_get(struct mem_range_desc *mrd, int *arg)
530 /* can we handle this? */
531 if (mem_range_softc.mr_op == NULL)
535 *arg = mem_range_softc.mr_ndesc;
537 bcopy(mem_range_softc.mr_desc, mrd, (*arg) * sizeof(struct mem_range_desc));
543 mem_range_attr_set(struct mem_range_desc *mrd, int *arg)
545 /* can we handle this? */
546 if (mem_range_softc.mr_op == NULL)
549 return (mem_range_softc.mr_op->set(&mem_range_softc, mrd, arg));
553 mem_range_AP_init(void)
555 if (mem_range_softc.mr_op && mem_range_softc.mr_op->initAP)
556 mem_range_softc.mr_op->initAP(&mem_range_softc);
560 random_ioctl(cdev_t dev, u_long cmd, caddr_t data, int flags, struct ucred *cred)
566 * Even inspecting the state is privileged, since it gives a hint
567 * about how easily the randomness might be guessed.
572 /* Really handled in upper layer */
576 intr = *(int16_t *)data;
577 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
579 if (intr < 0 || intr >= MAX_INTS)
581 register_randintr(intr);
584 intr = *(int16_t *)data;
585 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
587 if (intr < 0 || intr >= MAX_INTS)
589 unregister_randintr(intr);
595 intr = *(int16_t *)data;
596 if ((error = priv_check_cred(cred, PRIV_ROOT, 0)) != 0)
598 if (intr < 0 || intr >= MAX_INTS)
600 intr = next_registered_randintr(intr);
601 if (intr == MAX_INTS)
603 *(u_int16_t *)data = intr;
613 mm_filter_read(struct knote *kn, long hint)
619 mm_filter_write(struct knote *kn, long hint)
625 dummy_filter_detach(struct knote *kn) {}
627 /* Implemented in kern_nrandom.c */
628 static struct filterops random_read_filtops =
629 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, random_filter_read };
631 static struct filterops mm_read_filtops =
632 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, mm_filter_read };
634 static struct filterops mm_write_filtops =
635 { FILTEROP_ISFD|FILTEROP_MPSAFE, NULL, dummy_filter_detach, mm_filter_write };
638 mmkqfilter(struct dev_kqfilter_args *ap)
640 struct knote *kn = ap->a_kn;
641 cdev_t dev = ap->a_head.a_dev;
644 switch (kn->kn_filter) {
646 switch (minor(dev)) {
648 kn->kn_fop = &random_read_filtops;
651 kn->kn_fop = &mm_read_filtops;
656 kn->kn_fop = &mm_write_filtops;
659 ap->a_result = EOPNOTSUPP;
667 iszerodev(cdev_t dev)
669 return (zerodev == dev);
673 * /dev/upmap and /dev/kpmap.
676 user_kernel_mapping(int num, vm_ooffset_t offset, vm_ooffset_t *resultp)
682 if ((p = curproc) == NULL)
686 * If this is a child currently in vfork the pmap is shared with
687 * the parent! We need to actually set-up the parent's p_upmap,
688 * not the child's, and we need to set the invfork flag. Userland
689 * will probably adjust its static state so it must be consistent
690 * with the parent or userland will be really badly confused.
692 * (this situation can happen when user code in vfork() calls
693 * libc's getpid() or some other function which then decides
694 * it wants the upmap).
696 if (p->p_flags & P_PPWAIT) {
710 * /dev/upmap - maps RW per-process shared user-kernel area.
712 if (p->p_upmap == NULL)
713 proc_usermap(p, invfork);
715 p->p_upmap->invfork = invfork;
718 offset < roundup2(sizeof(*p->p_upmap), PAGE_SIZE)) {
719 /* only good for current process */
720 *resultp = pmap_kextract((vm_offset_t)p->p_upmap +
727 * /dev/kpmap - maps RO shared kernel global page
730 offset < roundup2(sizeof(*kpmap), PAGE_SIZE)) {
731 *resultp = pmap_kextract((vm_offset_t)kpmap +
743 mem_drvinit(void *unused)
746 /* Initialise memory range handling */
747 if (mem_range_softc.mr_op != NULL)
748 mem_range_softc.mr_op->init(&mem_range_softc);
750 make_dev(&mem_ops, 0, UID_ROOT, GID_KMEM, 0640, "mem");
751 make_dev(&mem_ops, 1, UID_ROOT, GID_KMEM, 0640, "kmem");
752 make_dev(&mem_ops, 2, UID_ROOT, GID_WHEEL, 0666, "null");
753 make_dev(&mem_ops, 3, UID_ROOT, GID_WHEEL, 0644, "random");
754 make_dev(&mem_ops, 4, UID_ROOT, GID_WHEEL, 0644, "urandom");
755 make_dev(&mem_ops, 5, UID_ROOT, GID_WHEEL, 0666, "upmap");
756 make_dev(&mem_ops, 6, UID_ROOT, GID_WHEEL, 0444, "kpmap");
757 zerodev = make_dev(&mem_ops, 12, UID_ROOT, GID_WHEEL, 0666, "zero");
758 make_dev(&mem_ops, 14, UID_ROOT, GID_WHEEL, 0600, "io");
761 SYSINIT(memdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,mem_drvinit,NULL)